1. Field of the Invention
This document relates to a display apparatus, and more particularly, to a sample for measuring an alignment axis for a liquid crystal display, a method of manufacturing the sample, and a method of measuring an alignment axis.
2. Description of the Related Art
Liquid crystal displays are generally devices displaying an image using optical anisotropy and birefringence properties of a liquid crystal.
In the liquid crystal displays, two substrates each having electrodes for generating electric field face each other so that the surfaces of the two substrates on which the electrodes are formed are opposite to each other, and a liquid crystal material is injected between the two substrates.
Alignment directions of the liquid crystal molecules are changed by electric field obtained by applying a voltage to the electrodes, and thereby the liquid crystal displays display an image by controlling the quantity of light transmitted through a transparent insulating substrates.
In the liquid crystal displays, a thin film transistor-liquid crystal display (TFT-LCD) using a TFT as a switching device has been generally used.
In the TFT-LCD, white light generated in a backlight unit passes through liquid crystal pixels such that transmittance of the white light is controlled. Then, the color screen is displayed using additive color mixtures of light transmitted through red (R), green (G) and blue (B) color filter layers positioned on the liquid crystal pixels.
Specifically, a driving principle of the liquid crystal display employs the optical anisotropy and the birefringence properties of the liquid crystal. Further, because the liquid crystal molecules have a thin and long molecule structure, the liquid crystal molecules have directionality and polarity in the molecules alignment and the alignment direction of the liquid crystal molecules may be controlled by artificially applying electric field to the liquid crystal molecules.
Accordingly, if the alignment direction of the liquid crystal molecules is optionally controlled, light may be transmitted or blocked depending on the alignment direction of the liquid crystal molecules due to the optical anisotropy of the liquid crystal. This results in the display of color and image due to changes in transmittance of light.
Since an initial alignment state of the liquid crystal molecules is determined by an alignment direction of the alignment layer, the alignment direction of the alignment layer and the polarized direction need to be known accurately.
However, since an anisotropic layer of the alignment layer is formed on only the surface of the alignment layer in the related art, it difficult to accurately measure the alignment direction.